Shrimp

Subphylum: Crustacea

The Subphylum Crustacea, is of more interest to aquarists, and contains six classes that I'm aware of with over 32,000 described species and many yet undescribed species. Before I go further, past thinking had the Order Decapoda placed in the 'Phylum' Crustacea, which was then divided into two suborders, 'Nantantia' containing the more interesting shrimp, and 'Reptantia' containing lobsters, crabs, and hermit crabs. The latest thinking is that "Crustacea" should now contain six classes and be a 'subphylum' of the 'Phylum Arthropoda.'

Only a few of those classes are of interest to hobbyists. The Class Maxillopoda containing barnacles was discussed above. The remaining two classes of major interest are Branchiopoda and Malacostraca, which contain by far the majority of animals we think of as crustaceans. Those in the Class Branchiopoda are mostly freshwater or brackish species, such as brine shrimp, usually incorrectly called Artemia salina, as this species is thought to be extinct. Yet one of the known species from the San Francisco area, Artemia franciscana, is regularly cultured for the aquarium trade. Another, the very common Daphnia pulex, would be familiar to freshwater aquarists, however, its also used as a marine fish food.

Nevertheless, those in the Class Malacostraca are of far more interest as it contains crabs, lobsters, prawns, shrimp, and crayfish. It's further divided into three subclasses, Phyllocarida, Hoplocarida and Eumalacostraca. As for Phyllocarida, its mostly ancient/primitive creatures, with most extinct. In the Subclass Hoplocarida, its Order Stomatopoda contains those dreaded mantis shrimps that are often undesirable in our aquariums.

In the Subclass Eumalacostraca, there are several superorders, two of which are of interest to marine aquarists. Its Superorder Peracarida contains small bottom-dwelling isopods and amphipods, along with small opossum shrimps we know as mysid shrimps.

The Superorder Eucarida contains two orders of significance. Order Euphausiacea contains the Pacific krill (Euphausia pacifica), which is an excellent foodstuff, either frozen or freeze-dried for our fish. And probably the most interesting is the Order Decapoda (meaning ten feet), which includes shrimps, prawns, lobsters, hermit crabs, and true crabs, and is composed of about 68 families containing almost 10,000 species.

This order is further divided into two suborders, Dendrobranchiata and Pleocyemata where those within it are classified by the structure of the gills and legs, and the way larvae develop. Those in the Suborder Dendrobranchiata release their eggs into the water and hatch as nauplii. And if shrimp are a people food in your household, a whole industry has been built around the culture of 'prawns' in this suborder. As for those in the Suborder Pleocyemata, its members cement their eggs to their pleopods (abdominal appendages) until they hatch, and these are of more interest to aquarists.

And once we move into the Suborder Pleocyemata, there are numerous 'infraorders' dedicated to various types of creatures, e.g., shrimp, lobsters, crabs, etc., and two have special interest if 'ornamental' type shrimp are of interest. In the Infraorder Stenopodidea, Family Stenopodidea, there's a very familiar species called the Banded Coral/Boxer shrimp Stenopus hispidus. However, it's not really considered a shrimp! It's considered more a lobster-like creature. And the Infraorder Caridea is where the more familiar 'true shrimp' genera begin to show up.

Order: Decapoda

(shrimps, prawns, lobsters, hermit crabs, true crabs)

Suborder: Dendrobranchiata
Superfamily Panaeoidea (penaeoid shrimps)
Family Aristeidae (gamba prawns & gamba shrimp)
Genera Aristaeomorpha; Aristaeopsis; Aristeus; Austropenaeus; Hemipenaeus; Hepomadus; Parahepomadus; Plesiopenaeus; Pseudaristeus

Family Benthesicymidae (benthesicymid shrimps)
Genera Bentheogennema; Benthesicymus; Benthonectes; Gennadas

Family Penaeidae (penaeid shrimps)
Genera Atypopenaeus; Farfantepenaeus; Fenneropenaeus; Funchalia; Heteropenaeus; Litopenaeua; Macropetasma; Marsupenaeus; Megokris Melicertus; Metapenaeopsis; Metapenaeus; Miyadiella; Parapenaeopsis; Parpenaeus; Pelagopenaeus; Penaeopsis; Penaeus; Protrachypene; Rimapenaeus; Tanypenaeus; Trachypenaeopsis; Trachypenaeus; Trachysalambria; Xiphopenaeus

Family Sicyoniidae (rock shrimps)
Genus Sicyonia

Family Solenoceridae
Genera Cryptopenaeus; Gordonella; Hadropenaeus; Haliporoides; Haliporus; Hymenopenaeus; Pleoticus; Solenocera


Superfamily Sergestoidea
Family Luciferidae
Genus Lucifer

Family Sergestidae
Genera Acetes; Pesisos; Petalidium; Sergestes; Sergia; Sicyonella



Suborder: Pleocyemata

Infraorder: Stenopodidea
Family Stenopodidae (Not shrimp - more lobster-like)
Genera Microprosthema; Odontozona; Stenopus

Family Spongicolidae (glass sponge shrimps)
Genera Microprosthema; Spongicola; Songicoloides; Spongiocaris


Infraorder:Caridea (true shrimp)

Superfamily Alpheoidea
Family Alpheidae (snapping/pistal shrimp)
Genera Alpheopsis; Alpheus; Athanas; Automate; Betaeus; Fenneralpheus; Leptalpheus; Metalpheus; Salmoneus; Salomeus; Synalpheus; Thunor

Family Hippolytidae
Genera Bythocaris; Caridion; Eualus; Exhippolysmata; Heptacarpus; Hetairus; Hippolysmata; Hippolyte; Latreutes; Lebbeus; Leptodius; Lysmata; Merhippolyte; Parhippolyte; Saron; Spirontocaris; Thor; Thoralus; Tozeuma; Trachycaris

Family Ogyrididae (longeye shrimps)
Genus Ogyrides

Family Barbouriidae


Superfamily Processoidea
Family Processidae (night shrimps)
Genera Ambidexter; Nikoides; Processa


Superfamily Pandaloidea
Family Pandalidae
Genera Bitias; Chlorotocus; Dichelopandalus; Heterocarpus; Mirpandalus; Pandalina; Pandalopsis; Pandalus; Pantomus; Parapandalus; Plesionika; Stylopandalus

Family Thalassocarididae


Superfamily Crangonoidea
Family Crangonidae
Genera Argis; Crangon; Lissocrangon; Mesocrangon; Metacrangon; Neocrangon; Paracrangon; Parapontocaris; Philocheras; Pontocaris; Pontophilus; Prionocrangon; Rhynocrangon; Sabinea; Sclerocrangon

Family Glyphocrangonidae (armored shrimps)
Genus Glyphocrangon


Superfamily Pasiphaeoidae
Family Pasiphaeidae (glass shrimps)
Genera Eupasiphae; Glyphus; Leptochela; Parapasiphae; Pasiphaea; Pasiphea; Psathyrocaris


Superfamily Bresilioidae
Family Agostocarididae
Genus Agostocaris

Family Alvinocarididae
Genera Alvinocaris; Chorocaris; Nautilocaris; Opaepele; Rimicaris; Shinkaicaris

Family Bresiliidae
Genera Bresilia; Encantada

Family Disciadidae
Genera Discias; Lucaya; Tridiscias

Family Mirocarididae
Genus Mirocaris


Superfamily Campylonotoidea
Family Bathypalaemonellidae
Family Campylonotoidae


Superfamily Palaemonoidea
Family Anchistioididae
Family Desmocarididae
Family Euryrhynchidae
Family Gnathophyllidae (bumblebee shrimp)
Genera Gnathophylloides; Gnathophyllum; Hymenocera (Harlequins); Levicaris; Phyllognathia

Family Hymenoceridae

Family Kakaducarididae

Family Palaemonidae
Genera Anchistioides; Brachycarpus; Cryphiops; Exopalaemon; Leander; Leptocarpus; Nematopalaemon; Palaemon; Palaemonetes

Subfamily Palaemoninae
Genera Macrobrachium; Urocaridella

Subfamily Pontoniinae
Genera Allopontia; Altopontonia; Amphipontonia; Anapontonia; Anchistus; Apopontonia; Araiopontonia; Balssia; Carinopontonia; Chacella; Chernocaris; Conchodytes; Coralliocaris; Coutierea; Ctenopontonia; Dasella; Dasycaris; Diapontonia; Epipontonia; Eupontonia; Fennera; Hamiger; Hamodactyloides; Hamodactylus; Hamopontonia; Harpiliopsis; Ischnopontonia; Isopontonia; Jocaste; Lipkebe; Mesopontonia; Metapontonia; Neoanchistus; Neopontonides; Notopontonia; Onycocaridella; Onycocaridites; Onycocaris; Orthopontonia; Palaemonella; Paraclimenaeus; Paranchistus; Parapontonia; Paratypton; Periclimenaeus; Periclimenes; Pericliminoides; Philarius; Platycaris; Platypontonia; Plesiopontonia; Pliopontonia; Pontonia; Pontonides; Pontoniopsis; Propontonia; Pseudocoutierea; Pseudopontonides; Stegopontonia; Tectopontonia; Thaumastocaris; Tuleariocaris; Typton; Veleronia; Veleroniopsis; Vir; Waldola; Zenopontonia

Family Typhlocarididae
Genus Typhlocaris


Superfamily Atyoidea
Family Atyidae (basket shrimp)
Genera Atya; Caridina; Jonga; Palaemonias; Paratya; Potimirim; Syncaris; Xiphocaris


Superfamily Galatheacaridoidea
Family Galatheacarididae


Superfamily Nematocarcinoidea
Family Eugonatonoidae
Genus Eugonatonotus

Family Nematocarcinidea
Genus Nematocarcinus

Family Rhynchocinetidae
Genera Cinetorhynchus; Rhynchocinetes

Family Xiphocarididae


Superfamily Oploporoidea
Family Oplophoridae (deepsea shrimps)
Genera Acanthephyra; Ephyrina; Heterogenys; Hymenodora; Janicella; Kemphyra; Meningodora; Notostomus; Oplophorus; Systellaspis


Superfamily Psalidopodoidae
Family Psalidopodidae (scissorfoot shrimps)
Genus Psalidopus


Superfamily Stylodactyloidea
Family Stylodactylidae
Genera Bathystylodactylus; Neostylodactylus; Parastylodactylus; Stylodactylus

One of the more valuable and interesting crustaceans in this order is cleaner shrimp, i.e., those that participate in the phenomenon of a cleaning symbiosis. This event involves the removal of parasites and other matter from various body parts of the infested fish, all in the name of a square meal. Their grooming/cleaning habits include climbing into the mouth of fish, cleaning their teeth and gill area, and/or picking small pieces of diseased flesh/bacteria from along the sides of the fish. To signal the willingness of the shrimp to perform the cleaning ritual they perform either a rocking motion or swaying of their antennae and/or front legs. Since community aquariums sometimes contain large fishes like angelfish, triggerfish, etc., which in turn like to eat shrimp, having both together in the same aquarium is a chancy situation, especially where the shrimp is concerned.

Even placing shrimp in the reef aquarium, where fish species are usually less aggressive, is still chancy. Not chancy for the shrimp, but chancy for other invertebrate, as some shrimps have a tendency to pick on corals and anemones. Yet, if you want to keep shrimp, the best habitat is that of a reef tank.

A question that arises every so often is what types of cleaner shrimp can be safely kept together in the same aquarium. Of the three most common, i.e., Lysmata, Periclimenes, and Stenopus, only the L. amboinensis and L. grabhami would be recommended as being safe to keep together in the same 'average size' aquarium. Even then, sufficient hiding places and a good supply of food is necessary to keep them from consuming each other. In larger aquaria with many hiding places and a good supply of food, different species can be maintained in the same environment.

As for molting in general, i.e., the shedding of its shell-like exterior (exoskeleton), it's an extremely important growth aspect for all shrimp. To grow larger, shrimp must shed this exoskeleton, as it will not stretch. Periodically, the shell-like covering begins to dissolve and separates from the body tissue while a new shell develops underneath. When the process completes, the shrimp climbs out of the old exterior covering and then takes up water, stretching the new soft covering to fit its now larger body. When finished, the new covering forms a hard exoskeleton. Keep in mind they are defenseless at molting time, therefore need secure hiding places that predators cannot reach.

Keep in mind all shrimp should be slowly acclimated to their new surroundings as they have a tendency to go into shock when entering an aquarium where water parameters are only slightly different from the shipping container. Temperature and especially Specific Gravity (S.G.) should be the same before transferring them into their permanent home. Contrary to what you may have heard, shrimp of any kind should never be given a freshwater bath to kill parasites prior to being added to the aquarium. It 'will' kill them, as they are very sensitive to changes in osmotic pressure. And as with all shrimp, low alkalinity, calcium, iodine and especially low magnesium levels can interfere with the molting process. In fact, magnesium 'must' be maintained at the proper level in relation to the S.G., or the molting process will not complete (Dr. Vincent Hargreaves, pers. com.). The lack of proper magnesium level is probably the main reason why many aquarists fail to maintain shrimp over the long term!

Superfamily Alpheoidea

Family Hippolytidae

Lysmata